Atrial fibrillation is a common problem that afflicts millions of patients. Unfortunately, atrial fibrillation often results in the formation of a thrombus, or clot, in the appendage of the left atrium. This presents a problem, inasmuch as the thrombus can dislodge and embolize to distant organs, resulting in adverse events such as a stroke. For this reason, most patients with atrial fibrillation are treated with a blood thinner so as to help prevent the formation of a thrombus in the left atrial appendage. Unfortunately, blood thinners pose a substantial health risk in their own right, particularly in the elderly.
An alternative treatment for atrial fibrillation is the ligation of the atrial appendage at its base. This procedure occludes the space in which the thrombus can form, thereby substantially eliminating the risk of forming a clot in the left atrial appendage and/or preventing a clot in the appendage from embolizing. Surgeons have been ligating atrial appendages for years during open surgical procedures. Though effective, this approach requires general anesthesia and surgically opening the chest, which presents additional serious health risks to the patient. Therefore, such open-chest ligation of the atrial appendage is normally restricted to situations where the chest is already being surgically opened for other reasons, or where the patient is at a particularly high risk of embolizing.
Recently, catheter-based techniques have been developed for occluding the left atrial appendage space by placing mechanical devices inside the left atrial appendage. This is done under fluoroscopic and/or echocardiographic guidance without the need for a major chest incision or general anesthesia. Unfortunately, however, these techniques require the implantation of mechanical intracardiac devices which, over time, may result in clot formation, incomplete occluding of the appendage space, infection, etc.